Eurolock turning, but not locking

You haven't described the door mechanism - but I had a problem with a UPVC door where the lock rollers were not travelling all the way into the slots due to a slight mis-alignment. This caused my lock not to work when the door was closed.

Sorry, not sure what to describe. It's a wooden, external door. The key mechanism is above the handle (counter-intuitively to me) and the key goes in upside-down. Judging from the plate I see on opening the door, I am guessing that it is one, integrated mechanism for the handle and lock, though they operate different tongues. It is made by Assa.

Thanks, I think you mean that the lock mechanism operates other devices as well, that secure the door on the sides/top-bottom; not the case with mine.

Kostas

If the Eurolock turns the problem is prolly in the sash lock case. Two screws hold a cover plate on, then you will find two screws & a machine screw. The machine screw secure the eurolock barrel - take the barrel out - you need to twist the key. The 'tab' either operates or it doesn't - assuming it hasn't snapped.

Check to make sure the bolt is able to enter the keep on the door frame, if the door has dropped it could be fouling the keep plate.

If it's an Assa it's probably not a euro cylinder, most Assa locks are what is termed as Scandanavian cylinders, either with an internal/external (oval shaped) cylinders or an external with thumbturn on inside. If the whole mechanism appears to work OK with the door open try removing one at a time each striking plate in the door frame until it works. What is stamped on the key, possibly OFG & a series of numbers?

If you count all the ones installed in Scandinavia, that seems likely. But the ASSA lock in my front door, and all the ones in some large office buildings I know are Euro cylinders.

That's very true but the fact that the cylinder is above the handle suggests to me that it is. Every domestic ASSA in my part of the world is what is known generically as a Scandinavian cyl. Other brands are Ruko, Boda, Trioving, Thomee to name a few.

This is int/ext. I cannot comment on the oval shape; the assembly that I fir the key in is oval shaped on one side. On the other side it's like some has been at the oval with a whole punch and created two crescents.

There is only one striking plate on the door frame. But wouldn't the effect in this case be that the key does not turn?

Yes, that's it.

Thanks, Kostas

Thanks, with the help of Google images I understood all the terms bar the "tab"; I guess it's what drives the lock-tongue in and out?

Kostas

Boda is mentioned on the door and frame faceplates.

Are these reputable locks? (Not sure which ones TMH meant in his comment about one needing fixed each week).

Kostas

Depends. If the internals of the lock are worn, the tab might operate the bolt ok when there's no resistance, but slip when resistance is applied. With the door open, what happens if you hold a piece of wood against the bolt to stop it coming out, and try to turn the key?

In my opinion they are one of the best. Your squirt of WD40 obviously did the trick, if you're happy that the mechanism works as it should with the door open then consider it fixed. Very occasionally the cylinders need replacing but the genuine Assa's are expensive, about £60-70 for a pair of the int/ext that you describe. Much cheaper ones are available.

It doesn't apply to the type of lock cylinder that you have.

Yes. The black bit in this picky

They are ASSA. Its not the same ones every week! There are 300+ in the student accomodation blocks & they get abused.

It depends. With the key on the inside it pushes the tongue out. With the key on the outside, sometimes it pushes it out and sometimes it doesn't. With my finger holding the tongue, it either pushes it or it doesn't; at no point does my pressure make any change like one would expect from slipping.

Thanks for this and all the other advice (all the other folks who took an interest as well).